单选题 Biometric access-control systems—those using fingerprints, voiceprints, etc., to regulate admittance to restricted areas—work by degrees of similarity, not by identity. After all, even the same finger will rarely leave exactly identical prints. Such systems can be adjusted to minimize refuels of access to legitimate access-seekers. Such adjustments, however, increase the likelihood of admitting impostors.
Which of the following conclusions is most strongly supported by the information above?

A、 If a biometric access-control system were made to work by identity, it would not produce any correct admittance decisions.
B、 If a biometric access-control system reliably prevents impostors from being admitted, it will sometimes turn away legitimate access-seekers.
C、 Biometric access-control systems are appropriate only in situations in which admittance of impostors is less of a problem than is mistaken refusal of access.
D、 Nonbiometric access-control systems—based, for example, on numerical codes—are less likely than biometric ones to admit impostors.
E、 (E) Anyone choosing an access-control system should base the choice solely on the ratio of false refuels to false admittances.

【正确答案】 B

【答案解析】[解析] 归纳题型首先看带有if，unless的选项，这样我们发现(A)，(B)有if或unless，(B)可以作为一个很好的归纳答案；(A)中的any、(C)中的’only、(E)中的solely都属于绝对化语言，必然不对；(D)中的“nonbiometrics”为新概念，也必然不对。